Boundary layer microphone

Abstract

A microphone may use boundary layer technology in concert with a concave reflector to produce improved sensitivity. The concave reflector may be arranged with respect to a boundary layer creating surface such that the sound waves are concentrated at the boundary layer creating surface. Thus, an intense compression layer is formed proximate to the boundary layer creating surface. A transducer may arranged in opposition to the boundary layer creating surface to convert the boundary layer energy into an electrical signal.

What is claimed is:  
     
       1. A microphone comprising: 
       a concave reflector;  
       a boundary layer creating surface opposed to said concave reflector; and  
       an electrical transducer arranged in the boundary layer created by said boundary layer creating surface.  
     
     
       2. The microphone of  claim 1  further including an electrical transducer arranged near said surface. 
     
     
       3. The microphone of  claim 1  wherein said concave reflector includes a parabolic reflecting surface arranged in opposition to said boundary layer creating surface. 
     
     
       4. The microphone of  claim 1  wherein said boundary layer creating surface is a curved surface. 
     
     
       5. The microphone of  claim 4  wherein said boundary layer creating surface is spherical. 
     
     
       6. The microphone of  claim 5  wherein said boundary layer creating surface is formed on a sphere. 
     
     
       7. The microphone of  claim 1  wherein said boundary layer creating surface is formed on a teardrop shaped element. 
     
     
       8. The microphone of  claim 2  wherein said transducer is part of a shotgun microphone. 
     
     
       9. The microphone of  claim 8  wherein said shotgun microphone telescopically and removably engages said reflector. 
     
     
       10. The microphone of  claim 9  including a stop to position one end of said shotgun microphone proximate to said boundary layer creating surface. 
     
     
       11. The microphone of  claim 1  wherein said boundary layer creating surface is positioned proximate to the focal point of said concave reflector. 
     
     
       12. The microphone of  claim 1  including an element, said boundary layer creating surface is formed on said element, said element having another surface which dissipates the boundary layer. 
     
     
       13. The microphone of  claim 2  wherein said transducer is sufficiently close to said surface to lie in the boundary layer when said microphone is in use.